The present disclosure relates generally to spectrometers and more particularly to compact spectral sensors for obtaining spectral information about visible scenes. Spectrometers are used for hyperspectral imaging (HSI) to identify levels of light intensity in multiple bands of the visible and/or infrared light spectrums. The spectral information or data can be used for a variety of purposes, including capture of images from stationary positions and/or from aircraft or other moving vehicles via sunlight reflected off the surface of the earth or sea to identify structures, personnel, terrain features, etc., as well as to allow identification of material constituents (e.g., color content) of a particular scanned structure or terrain feature. Hyperspectral data analysis in particular allows sub-pixel material identification by providing a spectral signature (e.g., multiple bands) for each viewed pixel of a captured image. Conventional spectrometers for such applications typically include a grating or prism for light dispersion along with a slit and a detector array. In various applications, however, it is desirable to provide light weight spectrometers (micro-spectral sensors) having small form factors, for example, for installation in small hand-held systems or small unmanned aerial vehicles (UAVs) used in military reconnaissance or other similar operations. The grating or prism in conventional HSI spectrometers dictates the sensor size and previous efforts to shrink these types of devices have met with only limited success. Moreover, the amount of light gathered by such conventional spectrometers is limited by the use of scanned slits and the grating structure, thus inhibiting the ability to image low intensity terrain features. Thus, there remains a need for improved spectrometer designs that can provide advanced HSI spectral data for small UAVs and other applications requiring small sensor size.